Sealing device in bearing housings

ABSTRACT

A sealing device for bearing housing intended to carry a bearing and a rotatable shaft mounted therein, which housing is divided along a diametrical plane into two halves, characterized thereby that the bore in the side walls of said bearing housing halves through which the shaft passes, is considerably greater than the shaft and internally provided with a ridge or a groove which seals against and acts as a fixing device for the peripheral portion of a side washer which surrounds the shaft and forms a sealing device either alone, together with the shaft or together with another annular member which is arranged around the shaft.

United States Patent Ullberg us] 3,656,824 Apr. 18, 1972 [54] SEALINGDEVICE IN BEARING I-IOUSINGS Primary Examiner-Robert G. NilsonAttorney-Howson and Howson [57] ABSTRACT A sealing device for bearinghousing intended to carry a bearing and a rotatable shaft mountedtherein, which housing is divided along a diametrical plane into twohalves, characterized thereby that the bore in the side walls of saidbearing housing halves through which the shaft passes, is considerablygreater than the shaft and-intemally provided with a ridge or a groovewhich seals against and acts as a fixing device for the peripheralportion of a side washer which surrounds the shaft and forms a sealingdevice either alone, together with the shaft or together with anotherannular member which is arranged around the shaft.

7 Claims, 12 Drawing Figures PMENTEOAPR 18 I972 SHEET 1 [1F 6PATENTEDAPR 18 I972 3,656,824 SHEET 80F 6 The present invention refersto a sealing device in a bearing housing intended to support a bearingand a rotatable shaft mounted therein, whereby said housing is dividedalong a diametrical plane in two bearing housing halves.

This type of bearing housing is generally used for ball or rollerbearings of different types. The bearing housing is commonly sealed offaround the through-shaft by means of a felt ring, which are inserted ingrooves in one or both walls of the housing.

A disadvantage in this sealing device is that it is hardly accommodatedfor sealing off liquids. Moreover dust, dirt sand or the like may stickto the felt ring and thereby wear against the shaft, a wear that can beof such an extent that the shaft even may be damaged.

Another drawback in said type of seals is that it for proper functiondemands a particular pre-treatment, before it is mounted, as itotherwise very soon will lose contact with the shaft, and then only willact as a slot seal.

A further disadvantage is that the felt ring may exert a very highpressure on the shaft during running in, which especially at high speedswill cause an abnormal increase in temperature. It has happened thatshafts have been blue-annealed due to the friction against the hardcontacting felt ring.

Lately rings of synthetic materials have been tested in order to achievea better constant contacting force against the shaft. Such syntheticmaterials are, however, improper from the aspect that they attract dustparticles due to the static electricity, which is generated when theshaft rotates. Therefore, it has lately been searched for new ways toattain more efficient sealing devices in bearing housings.

The present invention represents a solution to these problems.

The sealing device according to the invention is characterized therebythat the bore in the side walls of the bearing housing halves, throughwhich the shaft passes, is considerably greater than the shaft andinternally provided with a ridge or a groove whichseals against and actsas a fixing device for the peripheral portion of a side washer whichsurrounds the shaft and forms a sealing device either alone, togetherwith the shaft or together with another annular member which may bearranged around the shaft.

In order more thoroughly to explain the idea of the invention, somerepresentative embodiments of the sealing device will be described inthe following. It is hereby referred to the drawings attached of whichFIG. I shows a longitudinal cut through a bearing housing and FIGS. 1bto 1e illustrate the assembly procedure in a bearing housing accordingto FIG. 1.

FIG. 2 shows a cut through the same bearing housing having a somewhatdifferent shape of the seal.

FIGS. 3 to 7 show other embodiments of the side washer and FIG. 8 showshow the idea of the invention may be applied in double-bearing housings.

In the figures the lower half of a so-called plummet block is designated11 and the upper half 12. The halves are provided with a bearing seat 13for a spherical roller bearing 14, which by the aid of a clamping sleeve15 is secured to the shaft 16. The shaft 16 passes through bores 18 inthe side walls 17 of the housing, said bores being substantiallyconcentric to the shaft. In the inner sides of the bores there aregrooves 19, which are limited by two annular surfaces 110 and acylindrical surface 111. In the groove is fitted a side washer 112,comprising a plane annular disc 113 and an envelope surface 114,attached to the periphery of the disc. The side washer has in otherwords a section of L-shape. Around the envelope surface 114, a rubberring 118 has been fitted by vulcanization task cementing or in someother suitable way. The task of the rubber ring is to secure a staticsealing off between the side washer 112 and the walls of the groove 19.The rubber ring 118 is then in mounted state compressed between theenvelope surface 114 and the cylindrical surface 111. The externalsurface of the side washer 112 contacts axially against a sealinglip 115of rubber, which at its inner portion is integral with a body portion116 of rubber. The external surface 117 of the body portion is in planewith the side wall ofthe bearing'housing.

Assembly of a bearing housing according to FIG. -1 takes place as isschematically described in FIGS. lb to Is. FIG. lb shows the bearing 14secured to the shaft 16 by a clamping sleeve 15, said shaft having twoside washers 112 threaded thereupon, one on each side of the bearing.Outside the washers there are seals 119, which as mentioned abovecomprise a body portion 116 and a lip 115. FIG. 1c shows the next stepin the assembly. The shaft 16 arranged as shown in FIG. 1b, is put inthe lower bearing housing half 11.-It is noted that the spacer rings(not numbered) on either side of the bearing are also assembled at thistime (see FIG. 10). The side washers 112 are fitted into the grooves 19,in the side walls 17. The upper bearing housing half 12 is put in itsplace in the next step of the assembly operation as shown in FIG. 1d. Byaid of screws (not shown in the drawings), the two halves are screwedagainst each other, whereby the rubber rings 118 are compressed andmakes a static seal for the side washers 112. FIG. 1e illustrates howthe sealing rings 119 are mounted in accurate position. This is carriedout so that the sealing ring during rotation of the shaft 16 is forcedin against the side washer by the aid of an appropriate tool, e.g. ascrew-driver 120. When the axially external surface 117 of the sealingring is in plane with the side wall 17 of the housing the sealing ringhas reached its proper sealing position.

The simple sealing device described in connection to FIGS. 1 to 1e, maybe improved by a further sealing ring 119 b,

located within the very bearing housing. The task of this furthersealing ring is to prevent leakage of oil. This sealing device is thusonly used when it is necessary to prevent lubricants in liquid form toescape from the bearing housing. Due to space motives it may then beappropriate to turn around the side washer 112 as shown in FIG. 2.Usually some of the simplicity of the assembly is however hereby lost asit is necessary to use some sort of measurement to determine theaccurate position of the sealing ring 119 relative to the side washer 112.

It is common that a bearing housing of the actual type supports a shaftend. As such bearing housings conventionally have been provided withfelt ring seals arranged in both side walls, the shaft has usually beenallowed to pass through both of those walls. This implies of course agreat risk that the bearing will be contaminated. The sealing points arehereby two instead of one, which is theoretically possible, and air mayeasier pass through the bearing as there are air slits at each side ofthe bearing.

This circumstance has been taken into consideration when developing thepresent invention. As shown in FIG. 3, the side washer may on one sideof the bearing be substituted by a leakproof cover 121, the peripheralportion of which is designed exactly as the peripheral portion of theside washer 112, i.e. with an external rubber ring 118a. The abovedisadvantages thus are completely eliminated. The number of sealingpoints is reduced by 50 percent and the risk of percolation is totallyeliminated.

The side washer may be given several different shapes. FIG. 4 shows howit has been arranged to act as a lubricating device. A lubricant nipple122 is screwed into the side washer 1 12a, which is made of homogeneousmaterial, and is attached to the bearing housing in the same manner asthe side washer in the embodiments earlier described, i.e. by the twobearing housing halves being squeezed together around a collar 123, theperiphery of which is surrounded by a rubber pad l18b. By aid of thelubricating device the bearing as well as the seal may be lubricated.

As mentioned in the ingress, the invention is not limited to a sealingdevice comprising two elements, i.e. a side washer and a rubber seal.The sealing device may also be a single part, which is so designed thatit seals directly against the shaft. FIG. 5 shows such an embodiment,where the sealing member is a felt ring 124 fitted in a sheet metalholder 125, the periphery of which is surrounded by a rubber pad 118c.

FIG. 6 shows a somewhat modified embodiment of the side washer which inthis case comprises a holder 112b, which in its inner portion isprovided with a vulcanized rubber lip l24b which sealingly contacts theshaft.

FIG. 7 represents an embodiment of the sealing device, which comprisestwo annular members which are so designed that they together form alabyrinth. A side washer 1120 attached to the side wall of the bearinghousing in a manner earlier described, is provided with two outwardlyextending annular portions 126, 127. Cooperating with these there aretwo in the opposite direction extending annular portions 128, 129arranged on a metal ring 130, which is fitted to the shaft.

As hereinbefore has been mentioned a reduced number of sealing pointsimplies an improved bearing assembly also thereby that the risk ofcontamination of the bearing is reduced. Therefore, so-calleddouble-bearing housings have been developed which comprise one rollingbearing in each end of the same bearing housing. This involves of coursean extra cost especially regarding storekeeping as it is necessary notonly to keep the standard bearing housings in stock but also specialdouble-bearing housings.

According to the present invention it is, however, possible to combinetwo bearing housings in such a manner as shown in FIG. 8. The bearinghousings are connected by a tube 131 which at both ends is provided witha fixing device as has earlier been described. The advantage with thisarrangement is not only that the double-bearing housings may besubstituted by pairs of bearing housings according to the invention butthere is also a large gain in that by using different lengths of thetube 131 it is possible to meet any demand from the customer as todifferent axial assembly measures.

The invention adopts firstly a sealing device for bearing housings, butbecause this sealing device may be designed in different ways not onlyregarding shape but also regarding dimensions, the invention alsoincludes a bearing housing which is equipped with a sealing device asdescribed. Such a bearing housing may be manufactured in series so thatit may be used for different types and dimensions of bearings intendedfor different shaft diameters. One bearing housing may thereby merely bysubstitution of the sealing device be used for a great number of bearingand shaft dimensions. This implies an enormous gain from economicalaspects, as four different plummer block series may be substituted byonly one.

I claim:

1. In combination, a rotatable shaft member, a hearing assembly mountedon said shaft member, a housing enclosing said bearing assembly dividedalong a diametrical plane into two halves, said housing having anopening at least at one axial end of a greater diameter than the shaftand having an annular groove formed therein, a seal assembly comprisinga side washer of L-shaped configuration mounted in said grooveconsisting of an annular disc portion extending transversely to theshaft and an envelope portion confronting the groove and extendingtransversely to the disc portion, a resilient annular member mounted onsaid envelope portion under compression in said groove thereby providinga static seal and at least one sealing ring of resilient materialmounted on said shaft having a flexible lip engaging the annular discportion of said side washer.

2. The combination as claimed in claim 1 characterized thereby that thelip of the sealing ring contacts axially against the external surface ofthe annular disc portion of the side washer, whereby the axial externalsurface of the sealing ring is in plane with the side wall or the outerportion of the side washer, in order to facilitate the decision of theaccurate location of the sealing ring relative to the sealing surface.

3. The combination as claimed in claim 1 characterized thereby that theside washer acts as a fixing device for a radial seal, the lip of whichcontacts the shaft.

4. The combination as claimed in claim 1 thereby that the side washer isprovided with a device for additional lubrication of the bearing or theseal.

5. The combination as claimed in claim 1 characterized thereb that thehousing is so desigged that bearings intended for di erent shaftdiameters may used merely by substituting the side washer and eventuallyanother on the shaft mounted member.

6. The combination as claimed in claim 1 wherein said housing isprovided with annular grooves at opposite axial ends to accommodate aseal assembly at opposite axial ends.

7. The combination as claimed in claim 1 wherein said housing isprovided with a groove at opposite axial ends, a seal assembly at oneaxial end of said housing, and a cover member mounted in said groove atthe opposite end of said housing.

1. In combination, a rotatable shaft member, a bearing assembly mountedon said shaft member, a housing enclosing said bearing assembly dividedalong a diametrical plane into two halves, said housing having anopening at least at one axial end of a greater diameter than the shaftand having an annular groove formed therein, a seal assembly comprisinga side washer of L-shaped configuration mounted in said grooveconsisting of an annular disc portion extending transversely to theshaft and an envelope portion confronting the groove and extendingtransversely to the disc portion, a resilient annular member mounted onsaid envelope portion under compression in said groove thereby providinga static seal and at least one sealing ring of resilient materialmounted on said shaft having a flexible lip engaging the annular discportion of said side washer.
 2. The combination as claimed in claim 1characterized thereby that the lip of the sealing ring contacts axiallyagainst the external surface of the annular disc portion of the sidewasher, whereby the axial external surface of the sealing ring is inplane with the side wall or the outer portion of the side washer, inorder to facilitate the decision of the accurate location of the sealingring relative to the sealing surface.
 3. The combination as claimed inclaim 1 characterized thereby that the side washer acts as a fixingdevice for a radial seal, the lip of which contacts the shaft.
 4. Thecombination as claimed in claim 1 thereby that the side washer isprovided with a device for additional lubrication of the bearing or theseal.
 5. The combination as claimed in claim 1 characterized therebythat the housing is so designed that bearings intended for differentshaft diameters may be used merely by substituting the side washer andeventually another on the shaft mounted member.
 6. The combination asclaimed in claim 1 wherein said housing is provided with annular groovesat opposite axial ends to accommodate a seal assembly at opposite axialends.
 7. The combination as claimed in claim 1 wherein said housing isprovided with a groove at opposite axial ends, a seal assembly at oneaxial end of said housing, and a cover member mounted in said groove atthe opposite end of said housing.